Wildfire Smoke Update
forFriday, August 9, 2013 8:30 AM

Thanks to a change in the wind direction in the upper atmosphere, Montana is now downwind of many large wildfires across the west, whereas earlier this week we were mostly in the clear. Wildfire smoke blew over the state yesterday evening and overnight from several states, including Idaho, Washington, Oregon, and even northern California. That smoke is visible across much of western and central Montana this morning. However, because that smoke is high in the atmosphere, air quality here at the ground is GOOD at all reporting locations.

Air quality will remain GOOD throughout the morning and early afternoon as this high atmospheric smoke continues to blow east before the next round of smoke arrives later this afternoon. Red Flag Warnings remain in effect today across parts of southwest Montana, but also across much of the west where wildfires are upwind of us. The Warning comes mostly from the threat of thunderstorms this afternoon across southwestern Montana, but elsewhere, there is also the threat for thunderstorms, winds, and low relative humidity values. Given the good fire weather today, we should expect another round of smoke to blow over the state by later this afternoon. Air quality should remain generally GOOD as the smoke stays high in the atmosphere. Cumulative particulate concentrations may become MODERATE this evening in some southwest valleys, as well as far southeastern Montana.

Wildfire and smoke conditions can change rapidly on days like this. There will be another update this afternoon with the latest information and a look ahead to the weekend and early next week.

Residents near active fires and under plumes aloft need to remain aware of current
conditions and use the visibility guidelines
to guide their activity decisions as the situation changes.

Smoke is visible in the air over the Helena Valley this morning, but because that smoke is very high in the atmosphere, air quality at the ground is GOOD.

The smoke report below compares particulate levels where information is available
to MDEQ’s
Health Effects Categories. Real time particulate information is currently available in most of the larger urban
areas from several different sources including: DEQ run PM-10 BAMS and PM2.5 BAMS,
NWS ASOS visibility monitors, and USFS remote access Nephelometers and BAMS. These advisories represent conditions between
midnight and 8 AM and may change substantially throughout the day.

Locations and severity of forest fire smoke reports since midnight of the date above
at reporting stations.

Local impacts in areas immediately adjacent to active fires are expected to exceed
some or all of the advisory levels. DEQ recommends the use of local
visibility guidelines to evaluate possible health risks and make informed
activity decisions.